Regardless of how you’re taking care of your plants, whether in soil or hydroponically, pH level is a key feature of an ideal growing environment. Your plant’s growing medium can have an acidic, alkaline, or neutral pH level. Typically, most plants thrive at a slightly acidic pH – which measures about 5.5 to 6.5. If your plant’s medium measures above that, the pH level is alkaline. If it is below that, the growing medium is acidic.

Don’t panic if your plant’s growing medium is not at the pH level it should be. There are several ways to adjust the pH and fix this problem.

Things You Will Need

  • A pH testing kit
  • A watering can or jug
  • Commercial pH-altering solutions 


  • Wood ash, sulfur, lime, and phosphoric acid​​​

Step One 

Apply the usual fertilizer or nutrients that you use in your garden. Wait an hour if your plants grow hydroponically or twenty-four hours if your plants grow in soil before moving on to the next step.

Step Two 

Once the required amount of time has passed, test your plant’s growing medium. To do this, use a pH testing kit. Follow the pH kit’s supplied instructions to properly test your plant’s growing medium. Once the test is complete, read the pH level reading. Compare the reading with what the ideal pH level should be for the type of your plants. 

Depending on your plant’s pH level requirements, you may need to increase the pH level or lower it. If you are lucky, the pH may already be at the correct level for your plants. If this is the case, you do not need to do anything further.

Step Three

If your growing medium has a pH level that is too low for your plants, you will need to increase it. To do this, you can either add wood ash, lime, or a specifically formulated pH-raising solution to some water. Follow the supplied instructions to determine how much water you will need and how much pH-raising agent you should add. If the pH-raising agent is solid, it is best to leave it to steep in water for a couple of hours. 

If your growing medium has a pH level that is too high for your plants, you will need to lower it. To lower the pH level, you can use a specific pH-lowering solution, sulfur, or phosphoric acid to some water. Like the previous method, you should follow the supplied instructions to determine what water-to-substance ratio to use. If you’re adding a solid agent to water, allow it a few hours to steep.

Step Four

Once you have finished creating the required solution, apply it to your plant’s growing medium. In the case of plants growing in soil, simply water the plants with the solution as you would water them normally. For hydroponically grown plants, simply add the solution to your plant’s hydroponic solution.

Step Five

Once you have applied the adjusting solution to your plant’s growing medium, allow it some time to settle, and then test the pH level again. For plants that grow hydroponically, wait thirty minutes before testing, and for plants that grow in soil or other solid growing mediums, wait twenty-four hours before testing again.

Depending on the second pH test results, you may need to do another pH level adjustment treatment. If this is the case, repeat steps three to five.